The RadioWavz B4:1VA Air Core Voltage BALUN is a Ruthroff 4:1 voltage BALUN it has become a very popular BALUN, and can be used with both floating and symmetrical loads without modification. Designed to handle its rated power with a low
standing wave radio (SWR). It has 4 to 1 impedance ratio. Because of its air core it has the highest voltage break down ratings in its design class. The Air core BALUN won't saturate like the ferrite-core and, unlike ferrite-core wire-wound
BALUNs, single-layer wound BALUNs almost never have insulation breakdown problems. Frequency Coverage: 1.8 to 30 MHz. Good for matching a 200 ohm load to a 50 ohm load, or 300 ohm load to a 75 ohm load.